Neutrino temperatures and fluxes from the LMC supernova

The observation^1,2of neutrinos from the LMC supernova makes possible direct tests of the theory of supernova explosions and of properties of weakly interacting particles. Here we describe a combined analysis of the angular and energy distributions of the events observed in the Kamiokande and the 1MB detectors which determines the effective temperatures and fluxes of neutrinos and anti-neutrinos produced by the explosion. Our main result is that a simple model is consistent with the available data and in reasonable agreement with conventional models of supernova explosions. The parameters of the model are: a single temperature, T, of 4.1^+1.0_-0.4 MeV, a flux of electron anti-neutrinos of (O.5_-0.35 ^+0.2)×10¹⁰cm^-2 [total energy in v̄_e = (3.0^+1.7_-1.4 × 10⁵² erg)], and a poorly determined flux of 'scattered' (see below) neutrinos = (0.2-5)× 10¹⁰cm^-2. Several statistical tests were used to determine the acceptable range of these parameters. We have also set limits on possible high-temperature fluxes of neutrinos or anti-neutrinos that might result from matter oscillations^3,4.